1. Technical Field
The present invention relates to a compact imaging lens having high performance, which is used for a digital camera, a broadcasting camera, a movie camera, and the like.
2. Description of the Related Art
Conventionally, methods in which the entirety of a lens system is extended or only a portion of lenses that constitute the lens system is moved so as to be brought into focus (perform focusing) at subject distances from far to near are known (refer to Patent Documents 1, 2, and 3 (Japanese Unexamined Patent Publication No. 2011-232624, Japanese Unexamined Patent Publication No. 2006-053377, and Japanese Patent No. 3084810)). In order to shorten time until focusing, there is demand for a lens group (a focusing group) which moves while focusing to reduce the weight thereof, thereby lightening the burden on a focusing mechanism. In such a case, the method in which only a portion of lenses that constitute a lens system is moved to perform focusing is appropriate. The method in which only a portion of lenses is moved to perform focusing is used by a zoom lens or a fixed focus lens that adopts an inner focus system. A telephoto lens with a large aperture ratio, which is configured such that a focusing group is disposed adjacent to a stop, is also known to adopt the method.